| Lab 2.3.10.2: Switch port options - Overview Estimated time: 20 min. Objectives: Work with the Management Console User Interface Menus to determine the switch model number, MAC address and firmware revision Use the System configuration menu to configure Fragment Free operation Use the Port configuration menu to enable Full-Duplex operation Use the Port configuration menu to enable Port Fast operation Background: In this lab you will work with the Management Console interface menus to configure a switch to operate in Fragment-Free switching mode. You will also configure a port to enable Full Duplex and Port Fast operation. Most switches can be configured with these options. Fragment-Free Operation There are 3 modes switches can operate in; 1) Cut-through or Fast-Forward, 2) Store-and-Forward and 3) Fragment-Free. In Fast-Forward mode, the switch only reads the destination MAC address of the Frame header and then immediately forwards the frame. This mode is the fastest but can also forward collision fragments of less than 64 bytes (a runt). Store-and forward waits for the entire frame to be received (up to 1,518 bytes) before forwarding the frame. It is the slowest switching mode but results in the fewest errors. Fragment-free mode reduces delay by making the forwarding decision after the first 64 bytes have been received. This means that no runts will be forwarded which is the most common type of bad Ethernet frame. Fragment-free is the best compromise between speed and errors. Cisco switches can be set to operate in Store-and forward, Fragment-free or Fast Forward modes depending on the model. Full Duplex Operation When Full Duplex is enabled on a port it can double the bandwidth by allowing it to simultaneously transmit and receive. This means that a 10Mbps Ethernet port can operate at 20Mbps as long as the network interface of the attached device (NIC or router interface) can also support Full Duplex operation. Since a switch provides virtual circuit to the device with no collisions, this is dedicated bandwidth to the device. A 100Mbps Fast Ethernet port can operate at 200Mbps dedicated bandwidth. Full Duplex operation must be set for each port. Port Fast Operation When a switch port comes up it normally goes thru the normal 802.1d Spanning Tree states of Blocking, Listening, Learning, and then Forwarding. This process can take from up to 45 seconds to occur. When Port fast mode (spanning tree) is enabled, the Spanning Tree Protocol (STP) can transition the port's state from Blocking to Forwarding without going through the intermediate states of Listening and Learning. This can be beneficial especially in Novell Network IPX environments where the client request can sometimes timeout due to the time it takes for a switch port to respond. Tools / Preparation: Prior to starting the lab, the teacher or lab assistant should have a switch available with the default VLAN settings. A workstation with HyperTerminal should be available to console into the switch and an Ethernet connection should be available to Telnet into the switch. Since there may be only one switch available, the instructor should demonstrate this lab at a minimum and students should work in larger teams to get hands on. While one team is doing switch labs the others could be doing web-based research on switches at the Cisco web site URLs listed below. Before beginning this lab you should read the Networking Academy Second Year Companion Guide, Chapter 2 -LAN Switching. You should also review semester 3 On-line Lesson 2. The following is a list of equipment required. Windows PC w/ HyperTerminal installed (configured for console connection to switch) Cisco Switch (19xx or 28xx model) Console Cable (roll-over) Straight-through CAT 5 Ethernet Cable from the workstation to a switch Ethernet port Web Site Resources: LAN Switching basics General information on all Cisco products - (Scroll down to chapter 15 - Switches) 1900 / 2820 series Ethernet switches 2900 series Fast Ethernet switches 3500 series Gigabit Ethernet switches Cisco switch clustering technology Notes: Step 1 - Connect the workstation to the switch console port and turn the switch on. Wait a few minutes for the switch to "boot up" and it will display a menu of options known as the "Management Console" (1900 version). 1. What is the model number for the switch? 2. What is the Ethernet Address (Layer 2 MAC address) of the switch? 3. What is the switch firmware revision and type? Step 2 - Configure the switch for fragment-free operation. Select the [S] System option from the main menu and review the menu options under Settings 4. What is the current switch mode set to? 5. What menu option will allow you to change the mode? 6. What options are available? Step 3 - Configure a port for full duplex. 7. List the ports that are available to select from: Identify Port: 8. Is full duplex enabled? What option is used to enable it? Step 4 - Configure a Port for Port Fast mode. From the port configuration menu, Select the Port Fast configuration option from the menu. 9. What option selects Port fast? Step 5 – Check switch IP configuration. From the [N] Network Management option on the main menu, select [I] for IP configuration. 10. Does the switch have an IP address? If so, what is it?